Influence of Gibberellic Acid on Growth and Endogenous Auxin Level in Epicotyl and Hypocotyl Tissues of Normal and Dwarf Bean Plants

Application of gibberellic acid to the apex of dwarf bean plants (cv. Alabaster) stimulated the elongation growth of epicotyl and hypocotyl but showed no significant effect on elongation growth in a normal cultivar (‘Blue Lake’). Gibberellin-treatment of dwarf plants was characterized by about twofold increase in the level of endogenous auxin. Maximum increase in IAA level was observed after 48 h of GA treatment. There was less increase in IAA content in normal bean plants. — Gibberellin treatment to excised epicotyl and hypocotyl sections of either dwarf or normal cultivar showed no effect on elongation growth. However, a considerable increase in the auxin level was observed in the sections of the dwarf cultivar. The maximum effect occurred with only 1 h incubation in basal medium containing gibberellin. — The indolo-α-pyrone spectro-fluoremetric method for IAA determination was used.     

Frequent alterations of SLIT2–ROBO1–CDC42 signalling pathway in breast cancer: clinicopathological correlation

The aim of the study was to understand the role of SLIT2–ROBO1/2–CDC42 signalling pathways in development of breast cancer (BC). Primary BC samples (n=150), comprising of almost equal proportion of four subtypes were tested for molecular alterations of SLIT2, ROBO1, ROBO2 and CDC42, the key regulator genes of this pathway. Deletion and methylation frequencies of the candidate genes were seen in the following order: deletion, SLIT2 (38.6%) >ROBO1 (30%) >ROBO2 (7.3%); methylation, SLIT2 (63.3%) >ROBO1 (26.6%) >ROBO2 (9.3%). Majority (80%, 120/150) of the tumours showed alterations (deletion/methylation) in at least one of the candidate genes. Overall, alterations of the candidate genes were as follows: SLIT2, 75.3% (101/150); ROBO1, 45.3% (68/150); ROBO2, 15.3% (23/150). Significantly, higher alteration of SLIT2 locus was observed in triple negative breast cancer (TNBC) over HER2 subtype (P=0.0014). Similar trend is also seen in overall alterations of SLIT2 and/or ROBO1, in TNBC than HER2 subtype (P=0.0012); of SLIT2 and/or ROBO2 in TNBC than luminal A (P=0.014) and HER2 subtype (P=0.048). Immunohistochemical analysis of SLIT2, ROBO1/2 showed reduced expression, concordant with their molecular alterations. Also, high expression of total CDC42 (49/52; 94.2%) and reduced expression of phospho Serine-71 CDC42 (41/52; 78.8%) was observed. Coalterations of SLIT2 and/or ROBO1, SLIT2 and/or ROBO2 had significant association with reduced expression of phospho Serine-71 CDC42 (P=0.0012–0.0038). Alterations of SLIT2 and/or ROBO1, reduced expression of phospho Serine-71 CDC42 predicted poor survival of BC patients. Results indicate the importance of SLIT2–ROBO1–CDC42 signalling pathway in predicting tumour progression.     

Marker-assisted improvement of the elite restorer line of rice,RPHR-1005 for resistance against bacterial blight and blast diseases

This study was carried out to improve the RPHR-1005, a stable restorer line of the popular medium slender grain type rice hybrid, DRRH-3 for bacterial blight (BB) and blast resistance through marker-assisted backcross breeding (MABB). Two major BB resistance genes, Xa21 and Xa33 and a major blast resistance gene, Pi2 were transferred to RPHR-1005 as two individual crosses. Foreground selection for Xa21, Xa33, Pi2, Rf3 and Rf4 was done by using gene-specific functional markers, while 59 simple sequence repeat (SSR) markers polymorphic between the donors and recipient parents were used to select the best plant possessing target resistance genes at each backcross generation. Backcrossing was continued till BC ₂ F ₂ and a promising homozygous backcross derived line possessing Xa21 + Pi2 and another possessing Xa33 were intercrossed to stack the target resistance genes into the genetic background of RPHR-1005. At ICF ₄, 10 promising lines possessing three resistance genes in homozygous condition along with fine-grain type, complete fertility restoration, better panicle exertion and taller plant type (compared to RPHR-1005) were identified.     

Pluronic F-68 Stimulates Growth of Solanum dulcamara in Culture

The effects have been studied of the non-ionic surfactant, PluronicF-68, on the growth of transformed roots, callus and protoplastsof Solanum dulcamara L. Root growth was stimulated by additionof 0001–005% (w/v) of freshly-prepared, commercial gradePluronic to culture medium, with maximum increases in root freshand dry weights at 001%. Higher concentrations (05–10%w/v) of freshly-prepared Pluronic inhibited growth. A Pluronicfraction, prepared by passage through silica-Amberlite resin,retarded root growth even at concentrations that were stimulatorywith the commercial preparation. Similarly, commercial gradePluronic solutions stored at 4C or 22C for 5 d (‘aged’)also inhibited root growth. Roots grew faster on Pluronic F-68-treatedmembrane rafts compared with growth on commercially-availablerafts; such growth enhancement was comparable to that seen inmedium supplemented with 001% (w/v) freshly-prepared commercialPluronic. Callus growth was also stimulated by the addition of freshly-prepared,commercial grade Pluronic F-68 to medium, with maximum increasesat 01% (w/v); in contrast, 10% (w/v) Pluronic was inhibitoryto callus growth. The mean plating efficiency (15 d after plating)of protoplasts cultured at densities of 01–2010⁵ cm_–3was increased up to 26% by 01% (w/v) Pluronic, while 10% wasinhibitory. Both root and callus soluble carbohydrates and proteinswere increased by exposure to freshly-prepared, commercial Pluronic.Similarly, the specific activities of malate dehydrogenase andacid phosphatase were increased in Pluronic F-68-treated callusand roots. The biotechnological implications of these resultsare discussed in relation to the potential value of non-ionicsurfactants as growth-stimulating additives to plant culturemedia. Key words: Solanum dulcamara, Pluronic F-68, surfactant, transformed roots, callus, protoplasts, malate dehydrogenase, acid phosphatase     

Association of <Emphasis Type="Italic">IL-10</Emphasis> gene (−1082A&gt;G, −819C&gt;T and −592C&gt;A) polymorphism and its serum level with metabolic syndrome of north Indian subjects

Metabolic syndrome (MetS) is an inflammatory disorder, in which various cytokines play important role in tilting balance towards disease state. Interleukin-10 (IL-10) is an important antiinflammatory cytokine, but its genetic polymorphisms and serum levels in Indian MetS subjects are unknown. Three IL-10 gene polymorphisms (?1082A >G (rs1800896), ?819C >T (rs1800872) and ?592C >A (rs1800871)) were genotyped with PCR-RFLP in MetS subjects (n = 384) and age/sex matched control subjects (n = 386). Serum IL-10 was measured using enzyme-linked immunosorbent assay. Serum IL-10 level was significantly low in MetS subject and significantly correlated with clinicobiochemical parameters of MetS. Of three investigated promoter polymorphisms, IL-10 –819C > T and –592C >A were significantly associated with risk of MetS. The mutant alleles ?819T and ?592A of IL-10 gene polymorphism were significantly higher in MetS subjects compared to controls. Of the four different haplotypes obtained, common ACC haplotype and rare GTA haplotype of IL-10 polymorphisms were associated with MetS. The mean of fasting insulin and HOMA-IR were significantly different between the genotypes of both ?819 C >T and ?592C >A polymorphisms of IL-10 in MetS subjects. These results suggested that polymorphisms in IL-10 gene (?819C >T and ?592C >A), haplotypes (ACC and GTA) and serum level are significantly associated with risk of MetS. IL-10 ?819C >T and ?592C >A polymorphic variants are also significantly associated with insulin level and homeostasis model assessment-insulin resistance in north Indian MetS subjects.     

Seed Surface Architecture and Random Amplified Polymorphic DNA Profiles of Paulownia fortunei, P. tomentosa and their Hybrid

The surface patterns of winged seeds of Paulownia fortunei,P. tomentosa and P. fortuneixP. tomentosa were examined by scanningelectron microscopy. The pattern of reticulation on the wingsand seed coat of P. fortunei and the hybrid are comparable,while that on P. tomentosa is different and more elongated.Also, the wings are more extended at the oblong ends of theseeds in the former when compared to the wings of P. tomentosa.Distinct random amplified polymorphic DNA (RAPD) patterns wereobtained for the three taxa and P. kawakamii with five differentrandom oligonucleotide primers, suggesting that the method canyield genetic markers for differentiating the taxa. Also, Southernblot analyses of the RAPD products of the hybrid and the twoparent species revealed shared (inherited) genetic polymorphisms.Copyright 1999 Annals of Botany Company Paulownia species and hybrid, seed surface architecture, reticulated thickening, RAPD markers, Scrophulariaceae.     

INTERCELLULAR COMMUNICATION IN RAPIDLY PROLIFERATING AND DIFFERENTIATED C6 GLIOMA CELLS IN CULTURE

Glial cells in the brain are known to provide structural and functional supports to neurons. To sustain such a supportive role, they have developed cell-to-cell communicating gap junctional channels. The authors studied the effect of dbcAMP on gap junctional channels mediated communication in C6 cells, a rat glioma cell line. Quantitative assessment of coupled cells under microscope after microinjection of a fluorescent dye was taken as a measure of junctional permeability. An enhanced coupling between cells was observed following dbcAMP treatment and this elevated coupling was found to be dependent on the duration of exposure of cells to dbcAMP. The studies have focused on a subtle shift in the spatial organization of the functional channels to the processes of dbcAMP induced differentiated cells from the cell cytoplasms and membranes of dbcAMP untreated cells. Immunofluorescence study with affinity purified antibody against gap junction further confirmed the spatial distribution of gap junctional protein(s) in the processes and also showed an increase in the density of the protein at the intercellular spaces in dbcAMP induced differentiated C6 glioma cells.     

Experimental Infection of Nosema sp. Ghose in an Unnatural Host Lesioderma sericorne

ABSTRACT. Various doses of a microsporan parasite, Nosema sp., were fed to third and fourth instar larvae of Lesioderma sericorne that infested different types of stored grains. A spore dose of 3 × 10³ spores/individual resulted in a 39% infection rate, reduction in larval and adult weights, and mean spore concentrations of 1.28 ± 0.2 × 10⁸ spores/larva and 1.1 ± 0.2 × 10⁸ spores/adult. At the above dose, mortality was not well marked (about 35% in larvae and 25% in adults). At 3 × 10⁴ spores/individual, the rate of mortality increases to 80% in larvae and 60% in adults. However, more of the pest population (88% of larvae and 73% of adults) died at a dose of 3 × 10⁵ spores/individual. This dose produced mean spore concentrations of 3.91 ± 0.2 × 10⁸ spores/larva and 2.89 ± 0.2 × 10⁸ spores/adult. Insect death was caused by heavy damage to gut epithelia and fat bodies.     

Biology and immature stages of cotton stainers (Heteroptera: Pyrrhocoridae) found in Ghana

Biology and immature stages of four species of Dysdercus found in Ghana are studied in detail. Complete life cycles of the species are followed in the laboratory. The larval stages are fully described for the first time. Keys to distinguish the larvae and adults are constructed. Relationship between measurements of successive instars is discussed.